Related Experiment Video
Updated: Jul 8, 2026
Preparation of a Blood Culture Pellet for Rapid Bacterial Identification and Antibiotic Susceptibility Testing
Published on: October 15, 2014
How long does it take to "rule out" bacteremia in children with central venous catheters?
Samir S Shah1, Kevin J Downes, Michael R Elliott
1Children's Hospital of Philadelphia, Division of Infectious Diseases, Room 1526, North Campus, 34th Street and Civic Center Boulevard, Philadelphia, PA 19104, USA. shahs@email.chop.edu
Insights
Rapid detection of bloodstream infections in children with central venous catheters is possible. Gram-negative bacteria are identified fastest, suggesting early antibiotic discontinuation may be safe for stable patients with negative cultures.
Area of Science:
- Pediatric Infectious Diseases
- Clinical Microbiology
- Hospital Epidemiology
Background:
- Children with central venous catheters (CVCs) and suspected bloodstream infections (BSIs) often undergo prolonged hospitalization for empiric antibiotic therapy.
- Continuous monitoring blood-culture systems offer faster detection of BSIs, potentially shortening treatment and hospital stays.
Purpose of the Study:
- To evaluate the time to blood-culture positivity in pediatric patients with CVCs and laboratory-confirmed BSIs.
- To determine if bacterial category influences the speed of BSI detection.
- To assess the feasibility of discontinuing empiric antibiotic therapy based on early negative blood-culture results.
Main Methods:
- Retrospective cohort study of children with CVCs and laboratory-confirmed BSIs.
- Analysis of 200 BSI episodes.
- Multivariate Cox proportional-hazards regression to identify factors associated with time to blood-culture positivity.
Main Results:
- The median time to blood-culture positivity was 14 hours.
- Gram-negative bacteria were associated with the quickest detection.
- Predicted probability of culture positivity at 36 hours was high (99.2% for Gram-negative, 96.6% for any infection).
Conclusions:
- Time to blood-culture positivity varies by bacterial category, with Gram-negative bacteria detected most rapidly.
- Early discontinuation of empiric antibiotics (24-36 hours) may be safe for clinically stable children with negative blood cultures.
Background:
Children with central venous catheters and suspected bloodstream infection are often hospitalized for 48 hours to receive empiric antibiotic therapy pending blood-culture results. Continuous monitoring blood-culture systems allow for more rapid detection of bloodstream infection than previous blood-culture systems, a feature that may facilitate earlier determination of the true presence or absence of bloodstream infection and shorten empiric antibiotic therapy and duration of hospitalization.
Methods:
This retrospective cohort study included children with central venous catheters who were diagnosed with laboratory-confirmed bloodstream infection after evaluation in the ambulatory care setting.
Results:
Two-hundred episodes of bloodstream infection were included. The median patient age was 5.5 years. Central venous catheters were in place for a median of 80.5 days. Gram-negative bacteria accounted for 51% of infections as part of either a monomicrobial (25%) or polymicrobial (26%) infection. The overall median time to blood-culture positivity was 14 hours. The predicted probability for a culture being positive at 36 hours was 99.2% for infections caused by gram-negative bacteria and 96.6% for any infection after adjusting for age, catheter type, and recent antibiotic use. In a multivariate Cox proportional-hazards regression model, polymicrobial infections with > or = 1 gram-negative bacteria and monomicrobial infections caused by gram-negative bacteria were independently associated with an earlier time to blood-culture positivity after adjusting for age, catheter type, and recent antibiotic use.
Conclusions:
The time to blood-culture positivity depends on bacterial category. Bloodstream infections caused by gram-negative bacteria are detected most quickly. Our data suggest that discontinuation of empiric antibiotic coverage may be warranted in clinically stable children with central venous catheters if the blood-culture results remain negative 24 to 36 hours after collection.
More Related Videos
08:30One-day Workflow Scheme for Bacterial Pathogen Detection and Antimicrobial Resistance Testing from Blood Cultures
Published on: July 9, 2012
09:07Direct Microbial Identification using An Automated Microbial Identification System to Facilitate the EUCAST RAST Method Without Mass Spectrometry
Published on: May 24, 2024
Related Concept Videos
01:27Parentral Nutrition: Centeral and Peripheral Parental Nutrition
PN can be administered through two primary routes:
1. Central Parenteral Nutrition (CPN):
CPN involves delivering a high concentration of nutrients through a large vein. This is typically achieved using a Peripherally Inserted Central Catheter (PICC) or,...
01:26Urine Studies II: Urine Culture and Sensitivity Test
01:22Aneurysm IV: Nursing Management
01:29Endocarditis IV: Nursing Management
01:20Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...